Their initial focus will likely be on the heart condition-causing gene that they've already found success with, but there are other genes Mitalipov says he'd like to target, too. In those, the gene-editing technique replaced the gene in every one of the embryo's cells, preventing the "mosaicism" - when some cells are fixed and others are not - that happened in previous studies. In most cases, the embryo's genetic machinery then "pasted in" a non-mutated copy. "This would completely eradicate the gene mutation and this disease from the lineage of a family", Mitalipov says.
Because he and his team simply corrected mutated genes, they don't consider their work in line with efforts to create super-humans.
In the US, Congress has blocked any clinical trials with the aim of turning an edited IVF embryo into a baby. And CRISPR didn't target any other genes - collateral damage that plagued similar Chinese studies in 2015.
In a series of laboratory experiments reported in the journal Nature, the OR researchers tried a different approach. "This brings it closer to clinic, but there's still a lot of work to do".
The heart problem is just one of more than 10,000 conditions that are caused by an error in the gene.
This image shows the first sign of successful in vitro fertilization, after co-injection of a gene-correcting enzyme and sperm from a donor with a genetic mutation known to cause hypertrophic cardiomyopathy.
This is the first study to demonstrate that a gene-editing technique can be used in human embryos to convert mutant genes back to their normal version, the researchers said.
Once the gene was removed, the embryo's own fix systems replaced them with the healthy version.
The genetically-modified embryos were only allowed to grow for a few days before being destroyed as there was never intent to implant them.
New gene editing tools let scientists alter the DNA of living cells - from plants, animals, even humans - more precisely than ever before. They were not intended for implantation either. About 40 nations, including the United States and the UK, effectively prohibit or outlaw using the method to genetically engineer babies.
"We think this is the first and largest study from which you could draw some reasonable conclusions", said Dr. Paul Amato, an OHSU adjunct associate professor of obstetrics and gynecology and study co-author. The process works in three steps.
"I for one believe, and this paper supports the view, that ultimately gene editing of human embryos can be made safe".
The research, which was leaked in part last week, struck home for Marlo Urbina, a mother of 8-year-old twins in Portland. HCM has no known cure or treatment as its symptoms don't manifest until the disease causes sudden death through cardiac arrest. Her boy is a carrier, but her girl, Sofia, has the disease.
She was so moved by early reports of the research that she called OHSU last week to thank the researchers.
"I don't want to be negative with our own discoveries but it is important to inform the public of what this means", he said.
As rumors spread in advance of the publication, the story sparked comparisons with films like Gattaca and books like Brave New World, with their themes of genetic discrimination, DNA-as-destiny and the social dangers of tampering with human heredity. Harold and Leila Y. Mathers Charitable Foundation, the Moxie Foundation, the Leona M. and Harry B. Helmsley Charitable Trust, and Shenzhen Municipal Government of China.
The study makes progress toward using gene editing to prevent genetic diseases, but there's still has a long way to go before clinical testing can begin, says Janet Rossant, a developmental biologist at the Hospital for Sick Children and the University of Toronto.
The hope was that, by being given such template embryos could be purged of nascent genetic disease.
Scientists not involved in the project hailed it a landmark in genetics.
"The results were encouraging", Arnett said. "It needs to be regulated very closely and needs to be done in a very responsible way".
There's wide agreement that more research is needed on the technology itself as well as its ethical implications. "These findings suggest that this approach might potentially have applications for the correction of heritable mutations in human embryos in conjunction with PGD", a statement from Nature, which published the scientific findings today, reads. Mitalipov would like 100 percent.
However, opponents of such research say it creates great ethical concerns over genetic engineering and the potential for so-called "designer babies", born with certain traits like greater intelligence or athletic ability.